Spray gun



y 5 1939- P. w. HOVEY ET AL 2,

SPRAY GUN Filed Dec. 17, 1957 INVENTOR.

Patented May 2, 1939 UNETED STATS SPRAY GUN Preston W. Hovey and CharlesL. Thompson, Oakland, Calif.

Application December 17, 1937, Serial No. 180,358

Claims.

This invention, a spray gun, is primarily devised for the cleaning ofautomotive vehicles, although it lends itself to any purpose to which aspray gun can be applied, such as spraying in- ,5 secticides, paint,chemicals and lacquer, and has the particular advantage over usualltypes of spray guns in the fact that any fluid under pressure may besimultaneously mixed and sprayed with either one or two additionalfluids, and also 10 in the fact that in paint and similar sprayingoperations, a more uniform pattern is produced, and the spread of thepattern may be extended or retracted as may be desired, and in the caseof car washing, a coarse spray can be produced.

In the case of cleaning of automotive vehicles, naphtha or other solventis. used to remove greases and oils, and the application of the solventis usually conducted through the medium of rags, sponges, or brushes,using thereby an excess of solvent without obtaining any better resultsthan if just the correct amount for softening of the material wasapplied, and this spray gun is particularly adapted for properlyapplying the correct amount of solvent, as well as for the applicationof wash water in a coarse spray or as a direct, solid flow, and liquidsoap or other cleaner can be simultaneously mixed and sprayed or flowedwith the water, thereby providing more eflicient and rapid cleaning ofvehicles.

This invention is also particularly adapted to the spraying ofinsecticides, since one or two different chemicals in liquid or gaseousform can be simultaneously mixed and sprayed with water or other fluid.

The objects and advantages of the invention are as follows; First; toprovide a spray device which may be used selectively to intermix andsimultaneously spray or atomize two or three different fluids at 40will.

Second: to provide a spray device with a series and compound venturisystem to increase the dispersion and restrict the spread of thepattern.

Third: to provide a spray device with a suction-fluid tip imbeddedwithin a pressure-fluid tip with the suction-fluid tip beveled forinitial dispersion from one side of the body of fluid dispersion andrestrict the spread of the pattern. of the draw on the fluid.

Fourth: to provide a housing forming an air or vacuum chamber or waterconduit at will, and with the housing restricted or necked about the tipassembly to form an annular passage thereabout.

Fifth: to provide a removable, restricting tip for the neck of saidhousing, whereby the spray pattern may be varied as well as the finenessof the spray by removal or replacement of the removable tip.

Other objects'and advantages of the invention will become apparent as.the following description is read on the drawing forming a part of thisspecification, and in which similar reference characters are used todesignate similar parts throughout the several views, of which:

Fig. 1 is a longitudinal section through the invention with the headshown in full line.

Fig. 2 is an enlarged section through the head and is taken on a line2-2 of Fig. 3.

Fig. 3 is an end elevation of Fig. 2.

Fig. 4 is an enlarged section through the com bined mixing and atomizingtip and is taken on line 4-4 of Fig. 5.

Fig. 5 is an end elevation of Fig. 4.

Fig. 6 is adiagram illustrating the various connections for the spraygun.

The spray gun consists of a barrel and first fluid lead I!) which isdrawn into a neck II at one end and internally threaded at its other endas indicated at H! to form a tight joint with the threaded extension l3of the head M. A removable tip I5 is provided with a restricted ejectornozzle or spray tip l6 terminating in an interiorly countersunk,comparatively long ejector passage ll of uniform cross-section; thecombination of neck and tip features first permitting expansion, thengathering or restriction, followed by impingement within the passage I!previous to escape from the nozzle, therefore producing a very fine mistof restricted and uniform pattern.

Removal of the tip I 1 permits greater expansion of the spray patternand a different and larger size of mist globules results, and the spraygun is particularly suited for car washing, either by flow or spray,without the tip.

The pressure-fluid conduit or second-fluid lead l8 has one end l9 fixedin the head I4 and its other end it terminates at a point inwardly fromthe end M of the neck of the barrel ill, and is smaller in diameter,forming an annular fluid passage between the tube l8 and the insidewalls of the neck I l and which forms a venturi for the jet 2! whenfluid under pressure is admitted to the barrel.

The suction-fluid conduit or third-fluid lead or tube 22 is of smallerdiameter than the tube l8 and has one end 23 fixed in the head l4, and asuitable connection 24 communicates through a passage 25 with the tube22, and this conduit or tube has its other end 26 laid or imbedded inthe tube IS with the bottom wall of the tube functioning as bottom wallfor both tubes and forming a crescent-shaped passage between the tubes,and terminating within the tube in spaced relation to the end of tubel8, forming the mixing and atomizing zone. It will be noted that aportion of the bottom wall 21 of tube 22 replaces a portion of thebottom wall 28 of tube I8. The terminal end of tube 22 is beveled asindicated at 29, to an angle not less than 135 from the top of the tubein the direction of emergence of fluid from the tube, to present thefluid to a gradual exposure or draw to fluid forced under pressurethrough the crescent shaped passage and thus more intimately breaking upthe fluid for atomization.

A water connection 30 is secured in the head it and communicates througha passage 3| directly with the interior of the barrel ID.

A control valve for the compressed air or pressure fluid, of standardmake is shown and consists of a spring 32 which urges the valve 33 toits seat 3d, and which is released by depressing the button 35 to forcethe valve away from. its seat against; the pressure of the fluid, thevalve stem 36 seating on a resilient sealing washer 31 which packs thebore 38 against escape of fluid.

When the button 35 is depressed, the air passes through the connection39 into the spring cage 40 thence through the valve stem passage 4| inthe valve seat 34, into the bore 38 between the packing 37 and the valveseat. It then escapes through passages 42 into the annular chamber 43and thence into tube I8.

The valve is controlled by a finger release lever 44 which is pivoted at45 to the head It, and cooperates intermediate its length with thebutton 35.

The hose connection 39 is screwed into a threaded aperture 48. The hoseconnections for the various fluid intakes, especially for water andcompressed air, are preferably of the quick change types, which are wellknown in the art.

For cleaning automotive vehicles, the gun may be used either with orwithout the tip l5, depending on the fineness and force of spraydesired, the spray being coarser and having greater impact force withoutthe tip, and a source of compressed air All is connected to theconnection 39 through the usual flexible hose 48, and another flexibleconnection 49 communicates between the connection 24 and a supply 50 ofsolvent, such as naphtha or gasoline, and the hose 5! connecting to awater supply is omitted.

Depression of lever 45 permits the compressed air from the supply 41 topass through the tube l8, and as it passes the beveled tip 29 it createsa suction on the supply 50 and as the solvent emerges from the tip it isdrawn out along the bottom of the mixing tip as it is gradually wipedaway and converted into a fine spray from the top surface of the streamdownwardly, the beveled side walls protecting the stream at the sides,and the stream not being exposed to the action of the compressed air atthe bottom until all the superposed fluid has been atomized.

The stream 53 of solvent is thus simultaneously mixed with the air andatomized, the flow of the compressed air being indicated by the arrowstream 5 1, and the atomized mixture next eddies in the tip l5 andfinally emerges through the restricted nozzle ll, producing a restrictedpattern of very fine spray.

If the tip I5 is removed, the atomized mixture emerges from the end 20of the necked portion of the barrel, and results in a coarser and morescattered pattern.

If the cap 55 is applied to seal the water inlet 30, a different patternand fineness of spray is produced with increase in vaporization due tothe formation of a partial vacuum by the air passing through the neck,and is therefore of particular advantage in painting and lacquering.

If the water connection is left open, air is drawn in through the barrelI0 and about the mixing tip as indicated at 56, increasing theatomization and producing a greater dispersion of the fluid or solvent.

In cleaning vehicles, after the oily and greasy areas have been sprayed,and wiped when necessary, connection can be made to the water supply 52through the connection 5!, and the water used alone or in conjunctionwith the compressed air, and with or without tip l5, depending on theimpact force desired. The connection 49 can either be left open, or canbe changed over to a supply 50 of liquid soap or other cleanser, andair, water and soap are then selectable at will for use individually orin any combination of two or three. If Water under pressure, and thesoap alone are to be used, then it is necessary to remove the tip I 5 topermit the necessary suction.

When the compressed air is used in connection with water, the water maybe either under pressure or free, and for service stations where waterunder pressure is not available, this gun offers a distinct advantage,since practically any of these stations have a supply of compressed air.

When compressed air, water and soap are used together, faster and moreeflicient cleaning results than when water and soap alone are used.

For painting and lacquering, the gun may be used with or without tip l5and with the connection 30 either open or plugged, making four differentspray patterns and degree of atomizations available at will.

For insecticide spraying, any combination of fluids, one of which mustbe a gas, may be coin- I cidently mixed and sprayed, therefore, the gunis adapted to any kind of spray problem.

The gun is also ideally adapted to spatter work in the smaller sizes,since two colors can be simultaneously atomized, if desired, in twodifferent zones, providing a variegated pattern, or one color can beemployed, as for black and white.

It Will be understood that variations in construction and arrangement ofparts, which variations are consistent with the appended claims, may beresorted to, without detracting from the spirit or scope of theinvention, or sacrificing any of the advantages thereof.

We claim:

1. A spray gun, in combination, a pressurefiuid lead terminating in amixing and atomizing tip; and a suction-fluid lead of smaller diameterlaid or imbedded in one side of said mixing and atomizing tip forming apartly encompassing noncircular passage of uniform cross-section forpassage of pressure-fluid, and terminating in spaced relation to the endof said tip and within the tip and having its axis parallel with theaxis of said mixing and atomizing tip, and an encompassing fluid lead,surrounding said mixing tip and terminating in spaced relation beyondthe end of said tip, whereby a plurality of fluids may be coincidentlymixed and sprayed at will.

2. A spray gun comprising an air conduit terminating in a mixing andatomizing tip, and a minating therein in spaced relation to the ter'minal end thereof; a barrel forming a handle and surrounding saidconduits and terminating in a neck portion encompassing said mixing tipand forming an annular passage therebetween and terminating beyond theend of said mixing tip; an inlet connection for said barrel and an inletconnection, for each of said conduits.

3. A structure as claimed in claim 2, the terminal end of said suctionconduit being beveled from the top Wall in the direction of emergence offluid, and at an angle of not less than to cause gradual wiping away offluid as the fluid emerges from said suction conduit by air passing overthe top and about the sides thereof through said crescent-shapedpassage.

4. In a spray gun, a mixing and atomizing tip comprising an air conduithaving a terminal end; a suction conduit of smaller diameter than saidair conduit and imbedded into the under side of said air conduit forminga crescent-shaped air passage between the walls of the tubes andterminating within and in spaced relation to the end of said terminalend whereby air passes only about the top and sides of the suctionconduit to provide a wiping action on liquid emerging therefrom, toincrease the length of the draw on the fluid before completeatomization, thereby creating a spray of globules of liquid of uniformsize throughout the extent of the spray pattern.

, 5. A spray gun comprising a barrel forming a handle and having aremovable head at one end and terminating at its other end in a neckedportion; an air lead mounted in said head and terminating axially inspaced relation to the end and within the necked portion of said barreland being of smaller diameter forming an annular fluid passagethereabout; a fluid lead of smaller diameter than said air lead andhaving one end mounted in said head and its other end axially alignedwith said air lead and imbedded into the wall and terminating in spacedrelation to the end of said air lead and forming a crescent shapedpassage between the walls of the tubes to restrict action of air to aportion of the circumference and increase the length of draw on fluidemerging from said fluid lead by air under pressure passing through saidcrescent shaped passage; a manually controlled valve having an operatinghandle axially aligned and closely related to the wall of the barrel anda connection for said air lead; a connection for said fluid lead; and awater connection for said barrel.

6. A structure as claimed in claim 5; said fluid lead terminating in atip beveled from the top wall in the direction of emergence of fluidtherefrom and at an angle of not lessthan 135, to increase the length ofthe draw on emerging fluid by air projected through said crescent shapedpassage.

'7. A mixing and atomizing tip for spray guns comprising a first tubeterminating in a mixing and atomizing portion; a second tube of smallerdiameter and imbedded into the mixing and atomizing portion of the firsttube, forming a crescent shaped passage between the inner wall of thefirst tube and outer wall of the second tube and terminating in abeveled end in spaced relation to the end within the mixing and atomizing portion of the first tube, to increase the length of wipe or draw onfluid emerging from the sec- 0nd tube by fluid forced through thecrescent shaped passage,

8. A spray gun comprising a barrel necked at one end and having a headsealing the other end, a compressed air delivery tube mounted in saidhead and extending into said necked portion and terminating in a mixingand atomizing zone with in said necked portion in spaced relation to theend thereof; an air connection and a manually controlled valve for saidtube; a water connection for said barrel; a cap for sealing said waterconnection at will; and a fluid delivery tube mounted in said head andextending into said mixing and atomizing zone portion of said compressedair delivery tube and having its bottom wall in common with the bottomwall of said compressed air delivery tube and terminating within saidportion in spaced relation to the end thereof; and a fluid connectionfor said fluid delivery tube.

9. A structure as claimed in claim 8; said fluid delivery tube being ofsmaller diameter than said compressed air delivery tube and having itsbottom wall in common with the bottom wall of said compressed airdelivery tube, forming a crescent shaped passage between the tubes andover the end of the fluid delivery tube, said tubes having their axesparallel within the mixing and atomizing zone, said fluid delivery tubehaving the end thereof beveled at an angle of not less than 135 in thedirection of flow of fluid to provide a wiping action confined to thetop surface of the fluid emerging from said end, by the air passingthrough the crescent-shaped passage and over the inclined beveled end ofthe fluid delivery tube.

10. A structure as claimed in claim 8; and a tip for said necked portionof said barrel, removable and replaceable at will to change the patternand fineness of spray, an having a bore having a countersunk bottom andbeing equal in diameter to the diameter of said necked portion, and acomparatively long, restricted ejection passage of uniform cross-sectionextending from the countersunk bottom of said bore to the end of saidtip.

PRESTON W. HOV'EY. CHARLES L. THOMPSON.

